A machine commonly used for taking up e.g. oil from water is constituted by a belt uptaking machine, comprising an endless, inclined belt, the lower end of which is immersed in the water, and where the oil shall adhere to the ascending belt part of the rotating belt. At the other, upper end of the belt uptaking machine there is provided a device for scraping off oil from the belt. These belt uptaking machines are commonly installed in specialized ships, where the belt may be arranged in the upstream or downstream direction.
Under certain operational conditions the rotation of these belts counteract their own function. Most belt uptaking machines are intended for taking up from the front, like an elevator, where oil, often by means of booms, is collected and supplied to the belt and the oil thereupon is conveyed further upwards along the belt. The inlet system of these belt uptaking machines has proven itself to have some serious drawbacks, based on the fact that it is easily affected by the waves, thus that the taking up capacity is considerably reduced, although the speed has been reduced to below one knot. The problem is that the belt uptaking machine generates a wash, partly because the belt at its movement upwards "tears" along water, and partly because a counterpressure wash is formed when the uptaking means moves up and down through the mass of water. The water film thereby created by the wash efficiently prevents oil from adhering to the belt.